From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Xi Wang To: Daniel Vetter , Keith Packard Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, security@kernel.org, Xi Wang , Chris Wilson , stable@vger.kernel.org Subject: [PATCH v2 1/2] drm/i915: fix integer overflow in i915_gem_execbuffer2() Date: Mon, 23 Apr 2012 04:06:41 -0400 Message-Id: <1335168402-25174-1-git-send-email-xi.wang@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On 32-bit systems, a large args->buffer_count from userspace via ioctl may overflow the allocation size, leading to out-of-bounds access. This vulnerability was introduced in commit 8408c282 ("drm/i915: First try a normal large kmalloc for the temporary exec buffers"). Signed-off-by: Xi Wang Cc: Chris Wilson Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index f51a696..7c50e58 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1404,7 +1404,8 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data, struct drm_i915_gem_exec_object2 *exec2_list = NULL; int ret; - if (args->buffer_count < 1) { + if (args->buffer_count < 1 || + args->buffer_count > UINT_MAX / sizeof(*exec2_list)) { DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count); return -EINVAL; } -- 1.7.5.4